Question

我正在尝试运行hibernate教程（basic）中给出的程序。但是我遇到了错误。令人惊讶的是，控制台中显示的错误日志非常少。如果有人能告诉我出错的地方，我将不胜感激。在将其发布之前，我花了很多时间尝试解决它。以下是我的代码;

的hibernate.cfg.xml

<hibernate-configuration>
    <session-factory>
        <!-- Database connection settings -->
        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe;DB_CLOSE_DELAY=-1;MVCC=TRUE</property>
        <property name="connection.username">hr</property>
        <property name="connection.password">hr</property>
        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>
        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>
        <!-- Drop and re-create the database schema on startup -->
        <property name="hbm2ddl.auto">create</property> 
        <mapping resource="org/hibernate/tutorial/hbm/Event.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

Event.hbm.xml

<hibernate-mapping package="org.hibernate.tutorial.hbm">
    <class name="Event" table="EVENTS">
        <id name="id" column="EVENT_ID">
            <generator class="increment"/>
        </id>
        <property name="date" type="timestamp" column="EVENT_DATE"/>
        <property name="title"/>
    </class>
</hibernate-mapping>

测试类：NativeApiIllustrationTest

package org.hibernate.tutorial.hbm;

import java.util.Date;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

import junit.framework.TestCase;

public class NativeApiIllustrationTest extends TestCase {
    private SessionFactory sessionFactory;

    @Override
    protected void setUp() throws Exception {
        // A SessionFactory is set up once for an application!
        final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
                .configure() // configures settings from hibernate.cfg.xml
                .build();
        try {
            sessionFactory = new MetadataSources( registry ).buildMetadata().buildSessionFactory();
        }
        catch (Exception e) {
            // The registry would be destroyed by the SessionFactory, but we had trouble building the SessionFactory
            // so destroy it manually.
            StandardServiceRegistryBuilder.destroy( registry );
        }
    }

    @Override
    protected void tearDown() throws Exception {
        if ( sessionFactory != null ) {
            sessionFactory.close();
        }
    }

    @SuppressWarnings("unchecked")
    public void testBasicUsage() {
        // create a couple of events...
        Session session = sessionFactory.openSession();
        session.beginTransaction();
        session.save( new Event( "Our very first event!", new Date() ) );
        session.save( new Event( "A follow up event", new Date() ) );
        session.getTransaction().commit();
        session.close();

        // now lets pull events from the database and list them
        session = sessionFactory.openSession();
        session.beginTransaction();
        List result = session.createQuery( "from Event" ).list();
        for ( Event event : (List<Event>) result ) {
            System.out.println( "Event (" + event.getDate() + ") : " + event.getTitle() );
        }
        session.getTransaction().commit();
        session.close();
    }
}

登录控制台：

Jun 13, 2017 6:54:51 AM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.2.10.Final}
Jun 13, 2017 6:54:51 AM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Jun 13, 2017 6:54:51 AM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
Jun 13, 2017 6:54:52 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
Jun 13, 2017 6:54:52 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [oracle.jdbc.driver.OracleDriver] at URL [jdbc:oracle:thin:@localhost:1521:xe;DB_CLOSE_DELAY=-1;MVCC=TRUE]
Jun 13, 2017 6:54:52 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=fod, password=****}
Jun 13, 2017 6:54:52 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
Jun 13, 2017 6:54:52 AM org.hibernate.engine.jdbc.connections.internal.PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 1 (min=1)
Jun 13, 2017 6:54:52 AM org.hibernate.service.internal.AbstractServiceRegistryImpl stopService
INFO: HHH000369: Error stopping service [class org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl] : java.lang.NullPointerException

空指针即将到来：Session session = sessionFactory.openSession（）;它表示sessionFactory为null。

以下是我在类路径中添加的jar 我

Answer 1

我对hibernate.cfg.xml进行了一些更改，它开始工作。修改后的xml如下：

<hibernate-configuration>
    <session-factory>
        <!-- Database connection settings -->
        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:XE</property>
        <property name="connection.username">hr</property>
        <property name="connection.password">hr</property>
        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>
        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>
        <!-- Drop and re-create the database schema on startup -->
        <property name="hbm2ddl.auto">create</property>     
        <mapping resource="org/hibernate/tutorial/hbm/Event.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

我在这个xml中所做的更改是修改连接URL：

<property name="connection.url">jdbc:oracle:thin:@localhost:1521:XE</property>

无法运行基本的hibernate 5程序

1 个答案: